Poultry litter has a high potential for agricultural use as a fertilizer and soil conditioner due to its high concentration of nutrients. However, without prior treatment, this residue may contain heavy metals from animal feed, representing a potential soil pollutant. Thus, composting presents itself as a promising technique for improving the quality of the material and reducing its risks of contamination. Therefore, the objective of this work is to elucidate the chemical and spectroscopic transformations that occur in the structure of the organic matter from poultry litter for 120 days of composting, determining the degree of maturity of the compound in different stages of decomposition. In addition, determine how the structural change of organic matter during composting alters the availability of toxic nutrients and metallic elements in the environment and plants. Also, to evaluate the effect of application of humic acids isolated from poultry litter compound at different stages of decomposition in the defense mechanism against abiotic stress in rice plants metals. To do this, three experiments will be carried out: first to characterize the poultry litter compound and its humic substances in different stages of maturation (EI); the second to determine the transfer of toxic metals to the plant when it is fertilized with poultry litter at different stages of composting (IBD); and the third to evaluate the bioactivity of humic substances extracted from poultry litter (EIII). Thus, it is expected to determine the minimum time required for composting poultry litter can be applied in an environmentally sound way soil. Thus, to guarantee the use of a by-product in the form of an organic fertilizer with a greater bioavailability of nutrients of the compound to the plants, improving its characteristic as fertilizer, and a lower bioavailability of the heavy metals by their complexation in the stable fraction of the organic matter, reducing its polluting potential. In this scenario, it is hoped to find alternatives that transform this great agribusiness liabilities into a byproduct applicable in agriculture. In addition to providing information about the environmental safety of the use of the compound of the poultry litter and encourage their use, demonstrating the feasibility of using the extracted humic substances that compound protection against abiotic stress metals in plants, as an alternative form of use of this material.